It might be a little tricky. Keep in mind that if you’re describing them, that’s relatively easy. But if you want an illustration, be prepared to modify the images a lot.
Suits of armor were designed to protect from injurious impacts. The pieces overlapped each other, but had room for air to move through. Otherwise the knights would bake in the sun.
NASA hard suits, on the other hand, often had bellows connections over joints, a very weak design for defense, but necessary for air-tightness, (and “constant volume”).
You could work it, though. Hard suits with circular joints that moved in rotation look like armor. Depending on your need, you could add in other features too. NASA suits had umbilicals. You wouldn’t want that.
These would be a bit different since it supposed to be far in the future.
and they were actually riding large flightless birds in the story too...
lol